Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932247AbbHMTVS (ORCPT ); Thu, 13 Aug 2015 15:21:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51058 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754451AbbHMTVM (ORCPT ); Thu, 13 Aug 2015 15:21:12 -0400 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= To: , Cc: Christophe Harle , Duncan Poole , Sherry Cheung , Subhash Gutti , John Hubbard , Mark Hairgrove , Lucien Dunning , Cameron Buschardt , Arvind Gopalakrishnan , Haggai Eran , Shachar Raindel , Liran Liss , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Subject: [RFC PATCH 5/8 v2] IB/odp/hmm: add core infiniband structure and helper for ODP with HMM v3. Date: Thu, 13 Aug 2015 15:20:50 -0400 Message-Id: <1439493653-1191-6-git-send-email-jglisse@redhat.com> In-Reply-To: <1439493653-1191-1-git-send-email-jglisse@redhat.com> References: <1439493653-1191-1-git-send-email-jglisse@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9559 Lines: 307 This add new core infiniband structure and helper to implement ODP (on demand paging) on top of HMM. We need to retain the tree of ib_umem as some hardware associate unique identifiant with each umem (or mr) and only allow hardware page table to be updated using this unique id. Changed since v1: - Adapt to new hmm_mirror lifetime rules. - Fix scan of existing mirror in ib_umem_odp_get(). Changed since v2: - Remove FIXME for empty umem as it is an invalid case. - Fix HMM version of ib_umem_odp_release() Signed-off-by: Jérôme Glisse Signed-off-by: John Hubbard Signed-off-by: Haggai Eran --- drivers/infiniband/core/umem_odp.c | 145 ++++++++++++++++++++++++++++++++++ drivers/infiniband/core/uverbs_cmd.c | 1 + drivers/infiniband/core/uverbs_main.c | 6 ++ include/rdma/ib_umem_odp.h | 27 +++++++ include/rdma/ib_verbs.h | 12 +++ 5 files changed, 191 insertions(+) diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c index d3b65d4..bcbc2c2 100644 --- a/drivers/infiniband/core/umem_odp.c +++ b/drivers/infiniband/core/umem_odp.c @@ -42,7 +42,152 @@ #include #if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) + +static void ib_mirror_destroy(struct kref *kref) +{ + struct ib_mirror *ib_mirror; + struct ib_device *ib_device; + + ib_mirror = container_of(kref, struct ib_mirror, kref); + + ib_device = ib_mirror->ib_device; + mutex_lock(&ib_device->hmm_mutex); + list_del_init(&ib_mirror->list); + mutex_unlock(&ib_device->hmm_mutex); + + /* hmm_mirror_unregister() will free the structure. */ + hmm_mirror_unregister(&ib_mirror->base); +} + +void ib_mirror_unref(struct ib_mirror *ib_mirror) +{ + if (ib_mirror == NULL) + return; + + kref_put(&ib_mirror->kref, ib_mirror_destroy); +} +EXPORT_SYMBOL(ib_mirror_unref); + +static inline struct ib_mirror *ib_mirror_ref(struct ib_mirror *ib_mirror) +{ + if (!ib_mirror || !kref_get_unless_zero(&ib_mirror->kref)) + return NULL; + return ib_mirror; +} + +int ib_umem_odp_get(struct ib_ucontext *context, struct ib_umem *umem) +{ + struct mm_struct *mm = get_task_mm(current); + struct ib_device *ib_device = context->device; + struct ib_mirror *ib_mirror; + struct pid *our_pid; + int ret; + + if (!mm || !ib_device->hmm_ready) + return -EINVAL; + + /* This can not happen ! */ + if (unlikely(ib_umem_start(umem) == ib_umem_end(umem))) + return -EINVAL; + + /* Prevent creating ODP MRs in child processes */ + rcu_read_lock(); + our_pid = get_task_pid(current->group_leader, PIDTYPE_PID); + rcu_read_unlock(); + put_pid(our_pid); + if (context->tgid != our_pid) { + mmput(mm); + return -EINVAL; + } + + umem->hugetlb = 0; + umem->odp_data = kmalloc(sizeof(*umem->odp_data), GFP_KERNEL); + if (umem->odp_data == NULL) { + mmput(mm); + return -ENOMEM; + } + umem->odp_data->private = NULL; + umem->odp_data->umem = umem; + + mutex_lock(&ib_device->hmm_mutex); + /* Is there an existing mirror for this process mm ? */ + ib_mirror = ib_mirror_ref(context->ib_mirror); + if (!ib_mirror) { + struct ib_mirror *tmp; + + list_for_each_entry(tmp, &ib_device->ib_mirrors, list) { + if (tmp->base.hmm->mm != mm) + continue; + ib_mirror = ib_mirror_ref(tmp); + break; + } + } + + if (!ib_mirror) { + /* We need to create a new mirror. */ + ib_mirror = kmalloc(sizeof(*ib_mirror), GFP_KERNEL); + if (!ib_mirror) { + mutex_unlock(&ib_device->hmm_mutex); + mmput(mm); + return -ENOMEM; + } + kref_init(&ib_mirror->kref); + init_rwsem(&ib_mirror->hmm_mr_rwsem); + ib_mirror->umem_tree = RB_ROOT; + ib_mirror->ib_device = ib_device; + + ib_mirror->base.device = &ib_device->hmm_dev; + ret = hmm_mirror_register(&ib_mirror->base); + if (ret) { + mutex_unlock(&ib_device->hmm_mutex); + kfree(ib_mirror); + mmput(mm); + return ret; + } + + list_add(&ib_mirror->list, &ib_device->ib_mirrors); + context->ib_mirror = ib_mirror_ref(ib_mirror); + } + mutex_unlock(&ib_device->hmm_mutex); + umem->odp_data.ib_mirror = ib_mirror; + + down_write(&ib_mirror->umem_rwsem); + rbt_ib_umem_insert(&umem->odp_data->interval_tree, &mirror->umem_tree); + up_write(&ib_mirror->umem_rwsem); + + mmput(mm); + return 0; +} + +void ib_umem_odp_release(struct ib_umem *umem) +{ + struct ib_mirror *ib_mirror = umem->odp_data->ib_mirror; + + /* + * Ensure that no more pages are mapped in the umem. + * + * It is the driver's responsibility to ensure, before calling us, + * that the hardware will not attempt to access the MR any more. + */ + + /* One optimization to release resources early here would be to call : + * hmm_mirror_range_discard(&ib_mirror->base, + * ib_umem_start(umem), + * ib_umem_end(umem)); + * But we can have overlapping umem so we would need to only discard + * range covered by one and only one umem while holding the umem rwsem. + */ + down_write(&ib_mirror->umem_rwsem); + rbt_ib_umem_remove(&umem->odp_data->interval_tree, &mirror->umem_tree); + up_write(&ib_mirror->umem_rwsem); + + ib_mirror_unref(ib_mirror); + kfree(umem->odp_data); + kfree(umem); +} + #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM */ + static void ib_umem_notifier_start_account(struct ib_umem *item) { mutex_lock(&item->odp_data->umem_mutex); diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c index 53163aa..1db6a17 100644 --- a/drivers/infiniband/core/uverbs_cmd.c +++ b/drivers/infiniband/core/uverbs_cmd.c @@ -339,6 +339,7 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file, #if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) #if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) + ucontext->ib_mirror = NULL; #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM */ ucontext->umem_tree = RB_ROOT; init_rwsem(&ucontext->umem_rwsem); diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c index f6eef2d..201bde3 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -45,6 +45,7 @@ #include #include #include +#include #include @@ -298,6 +299,11 @@ static int ib_uverbs_cleanup_ucontext(struct ib_uverbs_file *file, kfree(uobj); } +#if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) + ib_mirror_unref(context->ib_mirror); + context->ib_mirror = NULL; +#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM */ + put_pid(context->tgid); return context->device->dealloc_ucontext(context); diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h index 313d7f1..36b72f0 100644 --- a/include/rdma/ib_umem_odp.h +++ b/include/rdma/ib_umem_odp.h @@ -37,6 +37,32 @@ #include #include +#if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) +/* struct ib_mirror - per process mirror structure for infiniband driver. + * + * @ib_device: Infiniband device this mirror is associated with. + * @base: The hmm base mirror struct. + * @kref: Refcount for the structure. + * @list: For the list of ib_mirror of a given ib_device. + * @umem_tree: Red black tree of ib_umem ordered by virtual address. + * @umem_rwsem: Semaphore protecting the reb black tree. + * + * Because ib_ucontext struct is tie to file descriptor there can be several of + * them for a same process, which violate HMM requirement. Hence we create only + * one ib_mirror struct per process and have each ib_umem struct reference it. + */ +struct ib_mirror { + struct ib_device *ib_device; + struct hmm_mirror base; + struct kref kref; + struct list_head list; + struct rb_root umem_tree; + struct rw_semaphore umem_rwsem; +}; + +void ib_mirror_unref(struct ib_mirror *ib_mirror); +#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM */ + struct umem_odp_node { u64 __subtree_last; struct rb_node rb; @@ -44,6 +70,7 @@ struct umem_odp_node { struct ib_umem_odp { #if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) + struct ib_mirror *ib_mirror; #else /* * An array of the pages included in the on-demand paging umem. diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index 9d32df11..987050b 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -49,6 +49,9 @@ #include #include #include +#if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) +#include +#endif #include #include @@ -1217,6 +1220,7 @@ struct ib_ucontext { struct pid *tgid; #if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING) #if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) + struct ib_mirror *ib_mirror; #else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM */ struct rb_root umem_tree; /* @@ -1730,6 +1734,14 @@ struct ib_device { struct ib_dma_mapping_ops *dma_ops; +#if IS_ENABLED(CONFIG_INFINIBAND_ON_DEMAND_PAGING_HMM) + /* For ODP using HMM. */ + struct hmm_device hmm_dev; + struct list_head ib_mirrors; + struct mutex hmm_mutex; + bool hmm_ready; +#endif + struct module *owner; struct device dev; struct kobject *ports_parent; -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/